360 THE EAR be irritable and moody, and there may be more or less headache. Consti- pation and loss of waight are present in cases of chronic brain abscess but at times the patient feels fairly well and may continue his work. 3. Manifest. In this stage the symptoms are in part due to compression of the brain, and in part to toxaemia resulting from the suppuration. a. Symptoms due to compression are headache, nausea, vomiting of the projectile type, slow pulse and subnormal temperature (see Fig. 185). Papill- oedema is frequently present and is usually more marked on the diseased side. Headache is one of the earliest symptoms and lasts as long as conscious- ness persists. Nausea and vomiting are unconnected with the ingestion of food and may recur several times a day. In many cases of brain abscess the patient has a ravenous appetite—a symptom not infrequently associ- ated with a favourable prognosis. The pulse, at first rather quick, gradually becomes slower, and may drop to 50 or 40. The temperature also becomes subnormal unless the condition is masked by coexisting meningitis or sinus thrombosis but even in these cases the pulse remains relatively slow. The patient is drowsy and his cerebration slow. He may have to be shaken gently before he answers a question, and relapses almost at once into his former semi-comatose condition. b. The symptoms due to the infection are rapid exhaustion and very marked emaciation; there is also a peculiar and very disagreeable odour of the breath. The appetite is poor, the tongue thickly furred, the patient pale and consti- pated and sordes form on the teeth. A blood count usually shows a well- marked leucocytosis. On lumbar puncture the fluid may be quite normal but more frequently there is an increase in the cells—chiefly small lympho- cytes. Even when the fluid is turbid it is usually sterile. 4. Terminal The terminal or paralytic stage is associated with coma and sometimes with convulsions. DIAGNOSIS. While in many cases it is possible from the signs and symptoms described above to say with some degree of certainty that a brain abscess exists, it is much more difficult and sometimes impossible to locate it for there may be no focal symptoms. There are, however, certain signs which, if present, point to a definite situation of the abscess. The pressure of the cerebrospinal fluid is important. If it is below 200 mm of water the suspected acute otogenic abscess is more likely to be cerebellar, while if the pressure should be above 300mm of water the abscess is invariably above the tentorium. ABSCESS IN THE TEMPORAL LOBE Localized headache over the temporal lobe may be present, and the patient may claw uneasily at the affected region. Tenderness on tapping over the temporal region is found in cases in which an extradural abscess is also present. Paresis of the third nerve is often present on the side of the lesion and is indicated by dilatation of the homolateral pupil. Ptosis may develop later, followed by paralysis of the external muscles supplied by the third nerve. Not uncommonly there are contractions of the facial muscles on the side of the lesion, especially of those concerned hi wrinkling up the skin of the forehead and in frowning. When asked a question the patient may repeat the same word over and over again—a condition known as 'perseveration'.